It doesn't affect me, but there are objective reasons for letting people choose their own fonts. My dad has dyslexia and generally has an easier time reading Comic Sans than other fonts. For (I think) obvious reasons his company isn't going to start sending all their HTML-formatted emails in Comic Sans, which means he artificially has to spend more time reading emails than he might otherwise, unless he wants to copypaste the message bodies into MSWord and convert it.
It doesn't affect me, but there are objective reasons for letting people choose their own fonts. My dad has dyslexia and generally has an easier time reading Comic Sans than other fonts. For (I think) obvious reasons his company isn't going to start sending all their HTML-formatted emails in Comic Sans, which means he artificially has to spend more time reading emails than he might otherwise, unless he wants to copypaste the message bodies into MSWord and convert it.